Do we really need a modern ignition?

[Charlie Cheap]

pmuller9, my statement about points is NOT that it is the best overall, but on the street we do not need a 100K volts to light the mixture. No doubt the electronics are better in modern computer-controlled engines, but the spark from points is inherently longer...up to about 4K rpm. MSD stands for Multiple Spark Discharge to duplicate the longer points spark. Even in their own testing for HP and Torque the difference is negligible. Points vs HEI at street RPM's = points Torque @ 3500 - 241 HP / HEI - 238 HP, 4000 - 370.9 / HEI - 370.5, 4500 - 384.9 / HEI - 379.0. With the Mustang 3.0 to 2.79 rear gears 4500 RPM equals way over 110 MPH. Even hot rodders seldom venture there on the street. I use Torque because it translates more directly to ECONOMY. Please, I HAVE STATED MANY TIMES, IF YOU HAVE A COMPUTER CONTROLLED ENGINE DO NOT GO BACK TO POINTS. I like them because there is no computer needed on my old 6-cylinder driver, and installing a computer ignition did me ZERO good...though I did not test it above 75 MPH.

 

[Charlie Cheap]

In my previous post the first MSD number listed was HP (points vs HEI), but the other two were Torque (points vs factory HEI). The numbers are MSD numbers taken off the Hot Rod network on line. Remember, I am not making a case to move backward from a computer-controlled system to points, but showing points are fine for street driving my modified 6-cylinder.

 

[pmuller9]

That's fine Charlie.
My last post was not intended as a counter point concerning electronic versus points ignition.
I was simply explaining the separate rolls that spark voltage and spark current play during ignition in an effort to dispel some misconceptions.
It was good of you to share your thoughts on the subject knowing you would get some controversy.

 

[wsa111]

Charlie, unless you have new points & tight bushings in the distributor, after a couple of days all that will end.
This is not the stone age.
Modern electronics kick ass.

 

[Charlie Cheap]

Billy, many tests have been done in real world situations, and with a points dizzy in proper tune, electronics does nothing for street driving at street RPM. That is not my old school thinking but actual testing. Distributors do NOT go bad after a few miles if they are good ones, and points go thousands of miles between adjusting. Most drivers are not...and before electronics...were not mechanics, but they drove their cars to work daily with little trouble. Maintenance is the real reason for electronics, plus the ability to work with a computer that controls timing, injection, and shifting. Re-curving a modified dizzy is a great idea to get the most out of an old points system. I love electronics and went to the same electronics school as Rush Limbaugh. I went to learn how to fix stuff and he went to be a DJ. Last I heard he is worth about $400,000,000.00 and me...I have a few thou $$ in the bank. We can hash this points/electronics thing to death and get no where. I like my wife's electronics fired Ford Edge with a turbo, and it gets 175 HP from 96 cubic inches. A points dizzy would not work in her car, and I DO NOT recommend anyone with a DSII or any other electronics ignition to go back to points. My only point...pun intended...is that points work fine...up to a POINT!

 

[Bill1958]

Looking at the spark waveform shows a high voltage spike that initially jumps the plug gap.
Once the air between the gap is ionized by the initial spark the gap resistance goes very low which drops the voltage to a low value and raises the current significantly.
It is the current that ignites the fuel and starts the flame front not the voltage and the more current the wider the spark and the more fuel molecules get targeted.
This is important to those that want to run a lean mixture at cruise to maximize fuel economy.

As the engine load and cylinder pressure increases the resistance between the plug gap increases which requires a higher voltage to initially jump the gap.
The ignition system needs to supply enough voltage to jump the gap at the engines highest cylinder pressure.
This also includes the gap between the distributor rotor and the cap which can be as high as 5Kv.
If the rotor phasing is off the voltage needed will be much higher.

In the case of the MSD, a capacitive discharge to the coil may be shorter than an inductive discharge but the current at the plug gap is much higher by several times in comparison to the standard street inductive system.

In all the cases so far the 300 six shows improvement in both low end power and fuel economy using the MSD ignition.

Do you need an electronic ignition on a street performance Ford six?
Surely it is not an absolute necessity. It depends on the person's goals.

If there is a nuclear EMP the vehicles with points will be running around the dead electronic ignition vehicles.

"If there is a nuclear EMP the vehicles with points will be running around the dead electronic ignition vehicles."

(big smile) Yep!

 

[Bronctopia]

"If there is a nuclear EMP the vehicles with points will be running around the dead electronic ignition vehicles."

(big smile) Yep!

I'm not so sure about this any longer.
After N Korea started popping off test nukes there were some actual EMP experiments done on modern cars.

Turns out the car ECUs faired pretty well.
Most are double Faraday shielded by the ECU case, and the body metal.

They did manage to basically glitch the ECU in a few, probably through saturation of sensor wires. But as I recall those were fine after a restart.

EMP pulses work their worst damage on really long conductors, like transmission lines. I think if anything in a car engine would be vulnerable it would be the coil(s). And those are common to both points and ECU fired spark engines.

I will admit that anyone still driving a points engine is probably much more likely to have a spare coil in vehicle tho.

 

[DON]

I agree, they work to a point. It’s the old how much money you want to spend will determine how fast you can go

 

[Bill1958]

I'm not so sure about this any longer.
After N Korea started popping off test nukes there were some actual EMP experiments done on modern cars.

Turns out the car ECUs faired pretty well.
Most are double Faraday shielded by the ECU case, and the body metal.

They did manage to basically glitch the ECU in a few, probably through saturation of sensor wires. But as I recall those were fine after a restart.

EMP pulses work their worst damage on really long conductors, like transmission lines. I think if anything in a car engine would be vulnerable it would be the coil(s). And those are common to both points and ECU fired spark engines.

I will admit that anyone still driving a points engine is probably much more likely to have a spare coil in vehicle tho.

Either way...I hope we don't find out by living thru it.

 

[aussie7mains]

Just want to throw in my 2 cents worth. The voltage across the spark plug gap is entirely down to the gap size, the cylinder temperate and pressure. If the gap is wide you need more energy to jump across, when voltage is high you need much better insulation to prevent arcing across to anything that is earthed. Ive seen evidence of this when i was working on natural gas bus engines, when the spark gap was new, we set them at .5mm, as they wore, the gap could widen to over 1mm. At this point our inductive ignition could fire the Bosch coils we used (one per plug) with up to 100joules of energy, over 60kv, but leads would arc over. So the main reason for the system was to fire the gas at high loads under boost conditions, we did consider the multi spark system but that held no advantage. Basicaly, the inductive system with solid state electronics was entirely adequate. I use an Australian made Bosch electronic system which has proven to be well up to my use, propane and up to 200kpa manifold pressure with 9:1 CR, which would be harder to fire than anything on petrol. IMO all the aftermarket stuff is mostly sales pitch, certainly for road use.

 

[bmbm40]

Like many I used points in various vehicles over the years and they usually worked fine. My 1970 Triumph bike still has them. But for me not having to check/inspect, adjust and replace points is good enough reason for having electronic ignition. Probably my imagination but my Bronco just seems to run better with DSII. Custom curve on the DSII is on my list for Phase 2 upgrades.

 

[Frank]

I've become fond of a hybrid points-fired ignition, using the TFI module with points. it seems to me to have the best of both worlds. works so well on one vehicle I've set up the fresh built 240 to use this as well.

 

[wsa111]

Like many I used points in various vehicles over the years and they usually worked fine. My 1970 Triumph bike still has them. But for me not having to check/inspect, adjust and replace points is good enough reason for having electronic ignition. Probably my imagination but my Bronco just seems to run better with DSII. Custom curve on the DSII is on my list for Phase 2 upgrades.

One of my DS11's custom curved will help you quite a bit.

 

[bmbm40]

I've become fond of a hybrid points-fired ignition, using the TFI module with points. it seems to me to have the best of both worlds. works so well on one vehicle I've set up the fresh built 240 to use this as well.

You mean like this?

Upgrade Points Distributor To Fire With A TFI Module

Converted my wife's daily driver to points-controlled electronic ignition using a Motorcraft ignition module off a '93 F150. Credit for this swap goes to gofastforless.com. I emailed the man who wrote the site to verify a couple of specifics, and he responded, which I appreciate. The goal of...

fordsix.com

I really liked that setup and your wife's daily driver!
Points should last a long time like that right?

 

[PSIG]

When we did points-fired module conversions on Gold Wings a zillion years ago in our cruising club, they would go 50-70k miles with no visible contact wear and two or three gap checks in that time to correct slowly shifting timing. I reset mine more often as I liked tight timing to save fuel. Use good points cam lube.

One of them got so bad that it would hardly run, popping and all. The group had to stop in some no-name town in Florida to reset his points gap to get him to the next stop. Good gator nuggets there. If it's only a weekender, you may not have to do any adjustments before your estate sale. Else, points replacement modules like Pertronix II and many others do the same but do not drift timing at all, and hardly any wiring mods like DuraSpark.

 

[nearGettysburg]

Absolutely.
This includes actual ignition timing.
There are a lot of engine builds presently going on and how many take the time to verify that the timing mark TDC is really piston TDC before installing the head.
The same with checking cam timing during installation.

That check is most certainly on my list as i rebuild my 200.

 

[DON]

I thought it was interesting that when I put MSD AL6-2 and blaster ss coil, the exhaust note sounded slightly different, a little more “crisp”, or sharper

 

[karkev]

I've had the same Pertronix and 1996 Accell coil in my 1964 Fairlane's 260 V8 since 2005. Not having to pop the hood to file or replace points in 19 years has been pretty awesome. Installed a Pertronix in my 1955 Chevrolet 210's 235 I6 in 2015 right after I purchased the vehicle and it also performs flawlessly. Electronic ignition and alternators are godsends.